(ABC) -- A Michigan man accused of robbing a credit union told police he needed the money to help pay for his daughter's chemotherapy treatments, authorities said.

Brian Randolph, 23, is accused of robbing the Vibe Credit Union in South Lyon, Michigan, on Aug. 12.

Randolph entered the building and passed a note demanding money, police said. While the note indicated he had a shotgun hidden in his clothes, he never revealed the firearm and police told ABC News that he said he did not actually bring a gun with him.

He has been charged with armed robbery and bank robbery and had his bond set at $500,000, police said.

After his arrest, Randolph told police his motive for the robbery was to help pay for his daughter's cancer treatments, authorities said.

Randolph told police that his insurance company was no longer paying for his daughter's chemotherapy treatments and that he robbed the credit union in a last-ditch attempt to find a way to pay for her treatments, according to South Lyon Public Information Officer Lieutenant Christopher Sovik.

Randolph's family, including the mother of his 1-year-old daughter, told local ABC affiliate WXYZ-TV that they think he was desperately trying to get money before his daughter's upcoming chemotherapy treatment. Asia Dupree, Randolph's girlfriend and mother of their 1-year-old daughter, told WXYZ-TV that their daughter Brialynn has retinoblastoma, a cancer that forms in the eye.

"I guess it was desperation. Time was ticking right before her appointment came up," Dupree told WXYZ-TV.

Randolph is scheduled to make his first court appearance today since his arraignment, but the name of his lawyer was not immediately available, according to the court clerk.